The invention relates to an electronic pattern stitching sewing machine, and more particularly it relates to a system in such a sewing machine to improve the appearance of seams in the different patterns which are stitched in series. This kind of sewing machine can memorize, by manipulation of pattern selecting switches, a number of different patterns to be stitched in combination or in series. In this case, the interconnecting stitch between the two different patterns is problematical. The invention is intended to solve this problem, and to improve the interconnecting stitch in accordance with the different patterns.
Generally the pattern sewing machine is preset to have the same needle position coordinate at the initial and last stitch of a pattern. This is because the pattern such as shown in FIG. 1 by way of example is not suitable. This pattern starts from the initial stitch 1 and terminates at the last stitch 5. In other words, this pattern starts from the needle position coordinate L and terminates at the needle position coordinate R. If such a pattern is stitched in series, the interconnecting stitch between the two patterns necessarily becomes large and deforms the appearance of the combined pattern. If a pattern starts and terminates at the same needle position coordinate as shown in FIG. 2, the interconnection between the two patterns becomes natural, and the combined pattern is never deformed by the interconnecting stitch.
With the recent development of an electronic sewing machine, it has become possible to stitch a number of different patterns in series, any of which are sometimes selectively inverted. Such combinations of different patterns are shown in FIG. 3 in which the pattern A starts and terminate at the same needle position coordinate L, the pattern B starts and terminates at the needle position coordinate R, the pattern C starts and terminates at the needle position coordinate M, and the pattern D is inverted. If such different patterns are directly connected by the interconnecting stitch as shown in FIG. 3, such as interconnecting stitch is unnatural and considerably deforms the combined pattern.
The present invention has been provided to eliminate such defects and disadvantages of the prior art. It is a primary object of the invention to automatically modify the interconnecting stitch between two different patterns to be stitched in series in accordance to the type of patterns.
It is another object of the invention to eliminate the unsmoothness of the interconnecting stitch between the different patterns to produce pretty stitches.
The other features and advantages of the invention will be apparent from the following description of the invention in reference to the preferred embodiments as shown in the attached drawings.